Information is provided on making electrical energy measurements that
can help you reduce your electric bill.

Both a general and a more detailed technical discussion are provided on:
electrical power (watts and kilowatts), and
electrical energy (watt-hours and kilowatt-hours).

Whether you are technically inclined or not there is
useful information in these notes for the typical
homeowner interested in measuring energy use in their home.

The subjects discussed are:

1. The general aspects of power, energy, and energy conservation.
2. Your power company meter, and two low cost instruments that can help
you make quantitative measurements.

These instruments are the Kill-A-Watt EZ, 4460 manufactured by
P3International, and the TED 1000 whole house system manufactured
by The Energy Detective, and limited discussion on the TED 5000 system.

Some of the information is applicable to other competitive instruments.

3. Data and a number of graphs are provided.
4. There are suggested experiments for power and energy measurement
of various electrical loads.
5. The sales pitch for residential power factor correction at the main panel
is shown to produce NO power or energy saving.

6. Four of the plots included in the book are shown below to illustrate how power
consumption may vary thru the day, the large variation from one day to another,
and how this smooths out when averaged over many days.

The plots are first shown with captions explaining each plot, and then
duplicated without the captions for easier comparison of the plots.

The following plots are with captions.

PE1 --- Plot 110812_B.

This is a plot of whole house power and voltage for one day
from midnight (0 time) to the next midnight (24 time) with a resolution of 1 second
where needed. The particular day was 12 August 2011. The blue curve is power in
kilowatts, and the black curve is voltage in volts.

The total energy used for this day was 37.6 kWh, about $ 4.90. Peak power was about 4.2 kW. Average power was 1.57 kW.
Min to max
voltage variation was 122 to 125 volts. The many, short in time, but large in power,
spikes are motor startup and are less than 1 second. These very short spikes have
little influence on your total electric bill.

My base power load thru the night is much higher than for the typical consumer. This
results from a considerable amount of equipment that runs 24 hours per day.

Generally I do not like to present graphs with a displaced 0. But, for voltage there
is seldom much change from a moderately narrow range so the scale is expanded
and zero is moved way below the graph.

All the plots shown here have exactly the same scale factors on the Y-axis for easy comparison.

PE2 --- Plot 110814HR-B2--8-12-11.

This plot is identical to PE1, except, the average power for
the preceeding hour is calculated from the 1 second average power
values of that hour, and plotted as a dot at the end time of the
one hour period.

Because the averaging time for each dot is 1 hour this means that the
numerical value for that dot is equal to the kWh of energy used in
that last hour.

The voltage is also averaged over the preceeding hour, but plotted
as connected dots.

You should be able to mentally overlay this average power plot with
the PE1 power plot, and see the relationship.

Power is blue, and voltage is red.

PE3 --- Plot 11-8-15--9-14--COMP-B1.

This plot is like PE2, but it is many days, one month, overlaid on top of each
other. The calendar range is from 8-15-11 thru 9-14-11. You can see the wide swing in
power use at a given time of day from one day to another. But, also note,
you can see a common general trend of use thru the day.

Power is blue, and voltage is red.

PE4 --- Plot 11--8-15--9-14--AVE-All-B.

This plot is derived from PE3, but it is like PE2.

Here is displayed the average of of all the values of PE3
at each hour. Note, how much more uniform the use is during
the day when many days are averaged together as compared to
the single day in PE2.

Because of daily variations in your power usage it is very difficult
to make energy comparisons form one day to the next to evaluate
the effect of changes you may make. But, also note, month to month
variations are going to include seasonal variations.

To a large extent you need to measure individual loads to evaluate
what a change in the load might do to energy consumption. Then use whole
house monitoring over some reasonable time frame to see how much
change in total energy consumption results from making many changes in small
loads.

You have permission to make and have in your possession one paper copy of the entirety of
this Energy web page for your own residential personal use. Copies of portions of this
web page are not allowed except as may be allowed under copyright law. Anything copied
from here must include this copyright notice.

This web page prints reasonably with Internet Explorer. Some browsers may split
the graphs over more than one page.

You are encouraged to print a copy of this web page to make easy comparisons of the graphs. The
four plots are duplicated at the end without captions to make adajacent comparison easier.